Clarke declares fitness

Adelaide - Australia vice-captain Michael Clarke says he's fit to play in the second Ashes cricket Test against England and has denied he was hampered in the first Test by a bad back.

Clarke produced a labored innings of 9 from 50 balls in his only bat in the first Test at Brisbane, but said on Wednesday he was restricted by tight bowling rather than any physical problem.

Clarke had a lengthy net session at the Adelaide Oval before declaring his fitness for the second Test, which starts on Friday.

Out-of-form fast bowler Mitchell Johnson did not bowl in the nets on Wednesday, though his potential selection rivals Ryan Harris and Doug Bollinger both delivered strong spells.